Sharapova's two-spot dip came after she lost to Serena Williams in the semifinals of the Sony Open, where the Russian was a finalist the previous three years. Petra Kvitova (No. 6) and Angelique Kerber (No. 7) both passed Sharapova, who has yet to make a final in five tournaments this year in her return from a shoulder injury that ended her 2013 season in August.

"When you know what you have achieved before and you know what kind of level you can play at, it's always tough to go through those moments where you feel like you have to build from absolutely nothing," Sharapova said at the Sony Open, addressing her comeback from her latest shoulder problem. "Because in the last few years, I felt quite healthy and I have been extremely consistent. I have had great results.

"And when you miss that period of time and when you're in that healing process, your mind is not on trying to win tennis matches. It's trying to work yourself to get back to that stage. So the expectations that you set, you always think of what you achieved before, and you expect that you're going to achieve it again. But realistically, you have to calm yourself down."

In other rankings news:

• Australian Open finalist Dominika Cibulkova reached a career high of No. 10 after making the semifinals in Miami. She is the third top-10 player to represent Slovakia, joining Karina Habsudova (former No. 10) and Daniela Hantuchova (No. 5).

• Caroline Wozniacki, who tumbled to a six-year low of No. 18 two weeks ago, climbed to No. 14 after a quarterfinal appearance at the Sony Open.

• Elina Svitolina, 19, supplanted Madison Keys as the highest-ranked teenager, at a career-best No. 35. The Ukrainian advanced to the fourth round at the Sony Open. The 19-year-old Keys is 36th.

• Coco Vandeweghe, a 22-year-old American, jumped from No. 104 to No. 82 after making the Miami fourth round as a qualifier.